{
  console.log(0b111110111); // 二进制 503 以0B开头 0b大小写均可 es6
  console.log(0o767); // 八进制以0O开头 503  es6
}
{
  console.log(Number.isFinite(15)); //true
  console.log(Number.isFinite(NaN)); //false
  console.log(Number.isFinite(1 / 0)); //false
  console.log(Number.isNaN(23)); //false
  console.log(Number.isNaN(NaN)); //true
}
{
  console.log(Number.isInteger(25)); //true
  console.log(Number.isInteger(25.0)); //true
  console.log(Number.isInteger(25.1)); //false
  console.log(Number.isInteger("25")); //false 接收的参数为Number类型
}
{
  console.log(Number.MAX_SAFE_INTEGER); //上限 9007199254740991
  console.log(Number.MIN_SAFE_INTEGER); //下限 -9007199254740991
  console.log(Number.isSafeInteger(10)); //true
  console.log(Number.isSafeInteger("a")); //false 参数为num类型
}

{
  console.log(Math.trunc(6.9)); // 取整 6
  console.log(Math.trunc(6.1)); // 6
  console.log(Math.trunc("3.1" as any)); // 3
}
{
  console.log(Math.sign(-5)); // -1 负数
  console.log(Math.sign(0)); // 0
  console.log(Math.sign(5)); // 1  正数
  console.log(Math.sign("5" as any)); // 1  正数
  console.log(Math.sign("a6" as any)); // NaN
}
{
  console.log(Math.cbrt(-1)); //-1 立方根
  console.log(Math.cbrt(-8)); //-2
}
